The belly button has a secretion and smell may be not good navel cleaning, local infection, umbilical ureteric fistula and other conditions caused. 1. do not do a good job of cleaning the navel: if not often to the navel and around the cleaning or not often bathed, and in the weather is hotter in the summer there will be increased sweating, resulting in the navel secretion, the local and the odor of the situation. 2. local infection: if you like to use your hands to pick the belly button habit will cause local skin breakage, causing infection, infection can be pus discharge, can also be accompanied by odor. 3. umbilical ureteric fistula: is due to the process of embryonic development, navel and bladder between the umbilical ureter is not completely closed, resulting in the navel part of the urine oozing out, resulting in the navel secretion also stinks of the situation. The situation of belly button with discharge and smell can not be relieved after doing a good job of local cleaning, it is recommended to go to the hospital, please ask the doctor to make a judgment, to clarify the cause of the disease.